IL18 and acute respiratory distress syndrome: Clinical and animal studies have shown that the activation of multiple inflammatory cells and the release of inflammatory mediators contribute to the development and progression of ARDS [10], and the associations between ARDS and inflammatory biomarkers, such as IL-18, red blood cell distribution width (RDW)/albumin ratio, and neutrophil-to-lymphocyte ratio (NLR), have been explored [11–13].